of his country, from the days of Newton to our
own,--Dr. Thomas Young, who died in 1829. Would he or I be the listener,
if we were side by side? However humble I might feel in such a presence,
I should be so clad in the grandeur of the new discoveries, inventions,
ideas, I had to impart to him that I should seem to myself like the
ambassador of an Emperor. I should tell him of the ocean steamers, the
railroads that spread themselves like cobwebs over the civilized and
half-civilized portions of the earth, the telegraph and the telephone,
the photograph and the spectroscope. I should hand him a paper with the
morning news from London to read by the electric light, I should startle
him with a friction match, I should amaze him with the incredible truths
about anesthesia, I should astonish him with the later conclusions of
geology, I should dazzle him by the fully developed law of the
correlation of forces, I should delight him with the cell-doctrine, I
should confound him with the revolutionary apocalypse of Darwinism. All
this change in the aspects, position, beliefs, of humanity since the
time of Dr. Young's death, the date of my own graduation from college!

I ought to consider myself highly favored to have lived through such a
half century. But it seems to me that in walking the streets of London
and Paris I shall revert to my student days, and appear to myself like a
relic of a former generation. Those who have been born into the
inheritance of the new civilization feel very differently about it from
those who have lived their way into it. To the young and those
approaching middle age all these innovations in life and thought are as
natural, as much a matter of course, as the air they breathe; they form
a part of the inner framework of their intelligence, about which their
mental life is organized. To men and women of more than threescore and
ten they are external accretions, like the shell of a mollusk, the
jointed plates of an articulate. This must be remembered in reading
anything written by those who knew the century in its teens; it is not
likely to be forgotten, for the fact betrays itself in all the writer's
thoughts and expressions.

The story of my first visit to Europe is briefly this: my object was to
study the medical profession, chiefly in Paris, and I was in Europe
about two years and a half, from April, 1833, to October, 1835. I sailed
in the packet ship Philadelphia from New York for Portsmouth, wher